Electric meter.



Patented Apr. 29, I902.

T. DUNCAN.

ELECTRIC METER. (Application fllgd Nqv. 10, l899. Renewefi Jan. 6 1902 (no'modem INTEGRATING wwweoow m: n'oams mans col. wmmmn. WASHINGTON. o c.

FFTcE.

ATENT THOMAS DUNCAN, OF CHICAGO, ILLINOIS, ASSIGNOR TO THE SIEMENS do HALSKE ELECTRIC COMPANY OF AMERICA, OF CHICAGO, ILLINOIS, A

CORPORATION OF ILLINOIS.

ELECTRlC METER.

SPECIFICATION forming part of Letters Patent N 0. 698,667, dated April 29, 1902. Application filed November 10, 1899. Renewed January 6, 1902- Se'rial No, 88,484- (No model.)

To [LZZ whmn it may concern:

Be it known that I, THOMAS DUNCAN, a citizen of the United States, and a resident of Chicago, in the county of Cook and the State of Illinois, have invented certain newand'useful Improvements in Electric Meters, (Case No. 64,) of which the following is a speoification.

This invention relates to improvements in integratingwattmetersof thelnduction-motor type for use in alternating-current systems of electrical distribution.

The object of the invention is to produce a simplified design of meter which will be capable of being economically constructed and which at the same time will be accurate in its measurements under all conditions and changes of service and load inductance.

In the accompanying drawings, Figure 1 is a front elevation, partially diagrammatic, of an integrating wattmeter embodying my improvements. Fig. 2 shows the manner in which the laminae of the magnetic cores are punched from a sheet of metalwithout waste. Fig. 3shows a U -shaped lamina as it appears on leaving the punch, and Fig. 4 the shape of the parts punched out of the U-shaped lamina and which form the laminae of ,the other core.

A designates the series field-coil of the meter; 13, its volt or shunt field-coils, two in number, and C adisk armature that is mounted to rotate freely between said series and voltcoils upon a spindle C, to which an ordinary registering mechanism R is suitably geared. As herein shown, the volt-coils B are placed above the armature upon the downwardlyprojecting poles of an inverted- U -shaped magnetic core D, while the series coil A is placed below the armature upon a rectangular magnetic core D, all of the coils being located, as usual, away from the center of the armature, so that there is no interference with the spindle C, which in the view shown in Fig. 1 passes behind the coils and their magnetic cores, as indicated by dotted lines in said figure. The coil A is connected in series in the work-circuit W and the coils B in shunt across the line, the self-inductance of the latter coils producing a phase displacement by reason of which the armature will be inductively. rotated. The lag produced by the core D alone will not, however, amount to ninety degrees, as is now well understood by those skilled in this art, and to increase such lag to the full quadrature necessary to accurate service under all conditions of load inductance auxiliary volt-coils B are mounted in inductive relation with respect to the main volt-coils B and connected reversely thereto in shunt across the work-circuit TV, with the effect of producing a resultant magnetic field lagging the full ninety degrees desired; The usual magnetic drag E serves to maintain the armature rotations proportional to the torque exerted.

The magnetic cores D and D of the meter thus described are complementary, the rec= tangular core D of the series coil being of j ustthe size and shape of the opening or re-- cess in the core D between the poles of the latter, and all of the proportions of the meterare calculated with reference to this condi-.

tion. In forming said cores a strip of sheet iron or steel is fed beneath a punching-press, which cuts off a rectangulan'piece d and also removes a rectangular portion cl from the middle of one side of this piece, leaving a remaining U-shaped portion 61 A suflicient number of said U-shaped laminae are then assembled and secured together in any suit able manner, as by clamping-screws (i to constitut-e said core D, while the same number of rectangular laminae cl, punched out in form ing said U-shaped laminae, are similarly assembled and secured together to constitute the core D. As the consequence of this mode of construction all waste of material in formcent to the armature upon a rectangular magnetic core, and a pair of volt field-coils mounted upon the opposite side of the armature upon the poles of a U-shaped magnetic core, substantially as described.

2. An electric meter provided with the series coil A, volt-coils B, and armature C mounted on a spindle O geared to a registering mechanism R, U-shaped laminated core D having volt-coils mounted on its poles, and a laminated core D upon which the series coil Ais mounted, said cores being formed of laminae d and d of which the laminae d are of the shape and size of the space between the poles of the laminae d and can be struck without waste from the latter, substantially as described.

3. An electric meter, comprising a disk armature C mounted on aspindle 0' connected with a registering mechanism, volt-coils B and auxiliary volt-coils B mounted above the armature upon the downwardly-projecting poles of a U -shaped laminated core D,

WM. F. MEYER,

J NO. W. MCKENZIE. 

